This invention relates to a cassette loader which achieves increased tape loading efficiency by performing certain steps to different cassettes simultaneously. High speed automatic cassette loaders are known. Representative Patents disclosing such loaders are U.S. Pat. Nos. 4061286 (King, Sr. et al), 3997123 (King), 3814343 (Bennett) and 4332355 (Zophy). As used in this application the term "cassette" refers to an industry standard audio cassette such as are shown in the drawings. See, e.g., FIGS. 5B and 5C. Such cassettes are formed of a pair of shell halves which are secured together by glue, screws, sonic welding or other means to form the body of the cassette. A pair of hubs are positioned within the shell halves 12, 13 and are designed to freely rotate. A length of leader tape, about 70 cm., is attached by its opposite ends to the hubs. Thus, as used in the cassette loader the cassette is already loaded with the leader tape. Cassette has a pair of capstan holes and a pair of reference holes on both sides, i.e., in both shell halves. The bottom of the cassette is open to permit access by record and playback heads, drive capstans, etc.
In the audio industry these cassettes are referred to as "C-O" cassettes since in this form the cassette has "zero" minutes of recorded material. The purpose of the cassette loader is to load a predetermined length of magnetic tape into the cassette after the cassette shell has been assembled with the hubs and leader tape inside the cassette shell.
One important step involved in properly loading a cassette is to "equalize" the leader tape already contained within the cassette shell. In order for the leader tape to be rapidly pulled out of the cassette without jerking, tangling or perhaps breaking, it is necessary to wind all of the leader tape onto the right side hub. This positions the leader tape so that when it is extracted from the cassette and carried to the splice block, it does not have to pass around a very sharp angle, which would be the case if any of the leader tape were wound around the left hand hub. By winding the leader tape onto the right-hand hub, the leader tape is pulled evenly and at a very shallow angle towards the splice block. In addition, the length of "dead" time at the beginning and end of each side of the cassette is about the same. Without equalization, the length of time between the end of the recorded material and the end of the cassette is very short in one direction of play and very long in the other direction. The end of the leader tape attached to the left-hand hub remains stationary.
All of the loop of the leader tape is formed from tape pulled from the right-hand hub as the leader tape doubles. In prior art processes, the step is carried out before the cassette is wound with magnetic tape. The same is true of the invention described below for the same cassette. However, another cassette which has already been equalized is being simultaneously loaded with magnetic tape.
Therefore, it is an object of the invention to provide a cassette loader which can perform certain processes to two different cassettes simultaneously thereby achieving substantial efficiency gains.
It is another object of the invention to provide a cassette loader which permits the leader tape of one cassette to be equalized while the leader tape of another cassette is being spliced to the magnetic tape to be wound into the cassette.
It is another object of the invention to provide a cassette loader which practices the method of the invention.
These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a cassette loader for loading a length of magnetic tape into a cassette having a relatively short length of leader tape pre-loaded into the cassette and attached by opposite ends to respective first and second cassette hubs. The cassette loader comprises a leader equalization position for holding a cassette; leader equalization means for winding the leader tape substantially completely onto one or the other of the first and second cassette hubs while the cassette is in the leader equalization position and a cassette loading position spaced-apart from the leader equalization position for loading a length of magnetic tape into a cassette which has previously been processed in the leader equalization position. Cassette loading means are provided for loading a length of magnetic tape into the cassette at the cassette loading position simultaneously with the operation of the leader equalization means on the cassette in the leader equalization position. Transfer means transfer successive cassettes from the leader equalization position to the cassette loading position. Ejection means eject cassettes loaded with magnetic tape from the cassette loading position to permit loading of another cassette for loading.
According to one preferred embodiment of the invention, the leader equalization position is vertically spaced apart from the cassette loading position.
According to another preferred embodiment of the invention, the cassette loader includes a leader extraction position and leader extraction means for extracting the leader from the cassette while the cassette is in the leader extraction position.
Preferably, the leader extraction position is spaced-apart from both the leader equalization position and the cassette loading position.
According to a preferred embodiment of the invention, the leader extraction position is vertically spaced-apart from the leader equalization position and horizontally spaced-apart from the cassette loading position.
According to one preferred embodiment of the invention, the transfer means for transferring successive cassettes from the leader equalization position to the cassette loading position comprises a cassette loading lever having an outwardly extending cassette supporting shelf thereon. The loading lever is movable to a first position wherein the cassette supporting shelf is positioned under the cassette and the cassette is supported on the cassette supporting shelf in the leader equalization position and to a second position wherein the cassette supporting shelf is withdrawn from under the cassette allowing the cassette to move vertically from the leader equalization position.
According to one preferred embodiment of the invention, when the cassette supporting shelf is withdrawn from under the cassette and the cassette moves vertically from the leader equalization position and into the leader extraction position.
Preferably, the loading lever is movable from the second position to a third position, and in moving from the second to the third position, the loading lever moves the cassette from the leader extraction position to the cassette loading position.
An embodiment of the method according to the invention comprises the steps of moving a cassette to be loaded to a leader equalization position, equalizing the leader tape by winding the leader tape substantially completely onto one or the other of the first and second cassette hubs while the cassette is in the leader equalization position, moving the cassette to a loading position spaced-apart from the equalization position for loading a length of magnetic tape into a cassette which has previously been processed in the leader equalization position, loading a length of magnetic tape into the cassette at the cassette loading position simultaneously with the operation of the leader equalization means on the cassette in the leader equalization position; and repeating steps (a) through (d) by transferring successive cassettes from the leader equalization position to the cassette loading position. After loading the cassette with magnetic tape, the cassettes loaded with magnetic tape are ejected from the cassette loading position to permit loading of another cassette for loading.
Preferably, the step of moving the cassette from the leader equalization position to the cassette loading position comprises the step of moving the cassette vertically.
According to one preferred embodiment of the invention, the method includes the steps of moving the cassette to a leader extraction position and extracting the leader from the cassette while the cassette is in the leader extraction position.
According to another preferred embodiment of the invention, the step of moving the cassette to the leader extraction position comprises the step of moving the cassette to a position which is spaced-apart from both the leader equalization position and the cassette loading position.
According to yet another preferred embodiment of the invention, the method includes the step of moving the cassette to a leader extraction position which is vertically spaced-apart from the leader equalization position and horizontally spaced-apart from the cassette loading position.
Preferably, the step of transferring successive cassettes from the leader equalization position to the leader extraction position comprises the steps of providing a cassette loading lever having an outwardly extending cassette supporting shelf thereon, moving the loading lever to a first position wherein the cassette supporting shelf is positioned under the cassette and the cassette is supported on the cassette supporting shelf in the leader equalization position while the leader equalization step takes place and moving the loading lever to a second position wherein the cassette supporting shelf is withdrawn from under the cassette allowing the cassette to move vertically from the leader equalization position.
Preferably, the invention includes the step of moving the loading lever from the second position to a third position, and in moving from the second to the third position, the loading lever moves the cassette from the leader extraction position to the cassette loading position.